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Commit 4f823def authored by Julian Anastasov's avatar Julian Anastasov Committed by David S. Miller
Browse files

ipv4: fix to not remove local route on link down 



When fib_netdev_event calls fib_disable_ip on NETDEV_DOWN event
we should not delete the local routes if the local address
is still present. The confusion comes from the fact that both
fib_netdev_event and fib_inetaddr_event use the NETDEV_DOWN
constant. Fix it by returning back the variable 'force'.

Steps to reproduce:
modprobe dummy
ifconfig dummy0 192.168.168.1 up
ifconfig dummy0 down
ip route list table local | grep dummy | grep host
local 192.168.168.1 dev dummy0  proto kernel  scope host  src 192.168.168.1

Fixes: 8a3d0316 ("net: track link-status of ipv4 nexthops")
Signed-off-by: default avatarJulian Anastasov <ja@ssi.bg>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 5dbebbb4

include/net/ip_fib.h

+1 −1
Original line number Diff line number Diff line
@@ -317,7 +317,7 @@ void fib_flush_external(struct net *net); 


/* Exported by fib_semantics.c */

int ip_fib_check_default(__be32 gw, struct net_device *dev);

int fib_sync_down_dev(struct net_device *dev, unsigned long event);

int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force);

int fib_sync_down_addr(struct net *net, __be32 local);

int fib_sync_up(struct net_device *dev, unsigned int nh_flags);

void fib_select_multipath(struct fib_result *res);

net/ipv4/fib_frontend.c

+7 −6
Original line number Diff line number Diff line
@@ -1110,9 +1110,10 @@ static void nl_fib_lookup_exit(struct net *net) 
	net->ipv4.fibnl = NULL;

}



static void fib_disable_ip(struct net_device *dev, unsigned long event)

static void fib_disable_ip(struct net_device *dev, unsigned long event,

			   bool force)

{

	if (fib_sync_down_dev(dev, event))

	if (fib_sync_down_dev(dev, event, force))

		fib_flush(dev_net(dev));

	rt_cache_flush(dev_net(dev));

	arp_ifdown(dev);
@@ -1140,7 +1141,7 @@ static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, 
			/* Last address was deleted from this interface.

			 * Disable IP.

			 */

			fib_disable_ip(dev, event);

			fib_disable_ip(dev, event, true);

		} else {

			rt_cache_flush(dev_net(dev));

		}
@@ -1157,7 +1158,7 @@ static int fib_netdev_event(struct notifier_block *this, unsigned long event, vo 
	unsigned int flags;



	if (event == NETDEV_UNREGISTER) {

		fib_disable_ip(dev, event);

		fib_disable_ip(dev, event, true);

		rt_flush_dev(dev);

		return NOTIFY_DONE;

	}
@@ -1178,14 +1179,14 @@ static int fib_netdev_event(struct notifier_block *this, unsigned long event, vo 
		rt_cache_flush(net);

		break;

	case NETDEV_DOWN:

		fib_disable_ip(dev, event);

		fib_disable_ip(dev, event, false);

		break;

	case NETDEV_CHANGE:

		flags = dev_get_flags(dev);

		if (flags & (IFF_RUNNING | IFF_LOWER_UP))

			fib_sync_up(dev, RTNH_F_LINKDOWN);

		else

			fib_sync_down_dev(dev, event);

			fib_sync_down_dev(dev, event, false);

		/* fall through */

	case NETDEV_CHANGEMTU:

		rt_cache_flush(net);

net/ipv4/fib_semantics.c

+8 −3
Original line number Diff line number Diff line
@@ -1281,7 +1281,13 @@ int fib_sync_down_addr(struct net *net, __be32 local) 
	return ret;

}



int fib_sync_down_dev(struct net_device *dev, unsigned long event)

/* Event              force Flags           Description

 * NETDEV_CHANGE      0     LINKDOWN        Carrier OFF, not for scope host

 * NETDEV_DOWN        0     LINKDOWN|DEAD   Link down, not for scope host

 * NETDEV_DOWN        1     LINKDOWN|DEAD   Last address removed

 * NETDEV_UNREGISTER  1     LINKDOWN|DEAD   Device removed

 */

int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force)

{

	int ret = 0;

	int scope = RT_SCOPE_NOWHERE;
@@ -1290,8 +1296,7 @@ int fib_sync_down_dev(struct net_device *dev, unsigned long event) 
	struct hlist_head *head = &fib_info_devhash[hash];

	struct fib_nh *nh;



	if (event == NETDEV_UNREGISTER ||

	    event == NETDEV_DOWN)

	if (force)

		scope = -1;



	hlist_for_each_entry(nh, head, nh_hash) {